Investigators are not sure why the woman's Mercedes SUV stopped on the tracks Tuesday night in Valhalla, about 30 miles north of New York City, National Transportation Safety Board Member Robert Sumwalt said Wednesday.
"For reasons not precisely known at this time, but for reasons that we intend to find out, the SUV was stopped on the tracks," he told reporters.
The SUV driver was identified as Ellen Brody, said Mushkee Raskin, program director at Chabad of the Rivertowns, a synagogue in nearby Dobbs Ferry. Brody was the mother of three girls, according to a friend of her family.
The gates at the crossing came down on top of her vehicle, said an MTA official with knowledge of the incident. She got out to examine the rear of her vehicle, then got back in, drove forward and was struck shortly before 7 p.m.
The vehicle was dragged 1,000 feet.
Some 400 feet of the electrified third rail perforated the first rail car and part of the second in 80-foot sections "breaking apart section by section, just basically piling up" in the cars, Sumwalt said.
Initial indications are the raging fire that consumed both the SUV and first rail car was fueled by gasoline from the vehicle, he said.
NTSB investigators have collected recording devices from the scene. Sumwalt said rail signals and the crossing arms at the intersection have recording devices.
All but one of the six dead were burned beyond recognition, Westchester County Executive Rob Astorino said. Dental records were being used to identify the victims.
One of the victims on the train was identified as Walter Liedtke, European paintings curator at the Metropolitan Museum of Art.
"We do not have official confirmation yet, but it appears as though he was among the victims in the first car," museum director Thomas Campbell wrote in an email to staff. "We are all shocked by this news and have his entire family, particularly his wife, Nancy, in our thoughts."
Eric Vandercar, 52, a senior managing director in institutional sales and trading for Mesirow Financial, also died in the crash.
"Eric was not only a pillar in our industry, he was a great partner and friend to many," Mesirow Financial said. "Losing him is a huge loss, personally and professionally. Our entire Mesirow family is hurting and our deepest sympathies are extended to his wife, Jill, and their family."
Joseph Nadol and Robert Dirks also died in the collision, according to New Castle, New York, Town Supervisor Robert Greenstein.
"On behalf of the Town of New Castle, we want to express our sincere condolences to the families and loved ones of Joseph Nadol of Ossining, Robert Dirks of Chappaqua and Ellen Brody, who worked at a local jewelry store," Greenstein said in a statement. "Our hearts are broken by this tragic accident."
Dirks worked at D. E. Shaw Research.
"Robert was a brilliant scientist who made tremendous contributions to our own research, and to the broader scientific community, during his eight years at D. E. Shaw Research," the company said in a statement. "He will be deeply missed as both a colleague and a friend. Our hearts go out to his wife Christine and their children."
Nadol was an analyst at J.P. Morgan.
"Joe will be dearly missed," J.P. Morgan said in a statement. "In addition to being an outstanding analyst, he was an exceptional colleague and friend. He was kind, thoughtful and had a wonderful sense of humor. Our thoughts and support are with Joe's wife, his three young sons and his entire family."
The sixth fatality on the train was Aditya Tomar, said Danbury, Connecticut, Mayor T. Mark Boughton. He also worked at J.P. Morgan.
"Aditya was an extraordinary colleague," the company said in a statement. "His leadership skills, sense of humor and tireless team spirit contributed to a better workplace for all of us in JPMorgan Asset Management. Our thoughts and support are with his wife and his entire family."
In addition, 15 people were injured, Gov. Andrew Cuomo said. It was the deadliest crash in Metro-North Railroad's 32-year history.
After the crash, passenger Justin Kaback said he hardly felt a thing when the commuter train smashed into the vehicle.
He didn't even know there had been an accident, or that the crash had killed six people.
The governor's office and the Metropolitan Transportation Authority on Wednesday morning revised the total number of fatalities, initially reported as seven.
Kaback said he received no warning of the fire about to ignite in the first car of the train.
The northbound train left New York's Grand Central Terminal more than an hour earlier, said Astorino, the Westchester County executive.
The scene was "horrific and unimaginable," he said. Engulfed by flames, the first rail car was a melted and charred hulk.
"To think about what these commuters went through when last night they got on the 5:45 train, probably talked to somebody at home, saying they're on their way and the world became upside down," Astorino told reporters.
The crossing where the crash occurred is "a little dangerous," he said. Traffic had been diverted to the area after an unrelated accident on a nearby highway.
"That's an area I think the state (Department of Transportation) needs to look at to see if we can improve," he said.
On Wednesday, eight people were still being treated at Westchester County Medical Center, including one in critical and another in serious condition, hospital officials said. Three suffered burns. Four were discharged overnight.
"The silver lining here is that the injuries and the extent of the injuries weren't as serious as they could be, comparatively, to some other major trauma activations," Dr. Joseph Turkowski, burn unit director, told reporters. "We could have received a lot more patients, a lot more serious injuries, and it could have resulted in a lot more deaths. We are thankful for that."
Emergency department director Dr. Ivan Miller said: "Many of us take Metro-North and we have families that take Metro-North. So it does strike close to home."
Inspectors from the National Transportation Safety Board are investigating.
"We will work closely with the NTSB and local officials to determine the exact cause of this tragedy, and work to ensure such incidents are not repeated," Metro-North Railroad President Joseph Giulietti said in a statement.
The cause of the crash has yet to be determined, but Astorino said: "At this point, all indications from the MTA at least is that it was not a problem with the tracks or anything. It was unfortunately human error, but that's part of the investigation."
Kaback, the passenger, who spoke with CNN's Don Lemon, said he felt only the train braking and coming to a complete stop, not the impact with the vehicle.
"They shut down the engine. They cut power. They cut the air," he said. Then there was silence.
The first word of anything gone wrong came from other passengers. They came back from the front of the train, saying they smelled gasoline.
"We've got to move to the back of the train," Kaback said they told him.
While the passengers fled the gas fumes, a short announcement over the train's loudspeakers told passengers that the train had struck a car, he said.
He said he heard no further details or instructions.
'The train is on fire'
Outside the train, somebody yelled, "The train is on fire," and the car he was in was growing hotter, Kaback said.
He said he felt claustrophobic.
"That's when I knew it was time to get off," Kaback said. The other passengers did, too. They threw open emergency doors and broke windows, he said. Everyone exited in an orderly manner without panic.
The snow on the ground, which sloped sharply down from the track, made climbing off the train difficult.
Once outside, Kaback took pictures of the first car of the train, as flames climbed out its windows.
Photos of the scene and aerial video from CNN affiliate WCBS
showed flames and smoke pouring out windows of the commuter train.
The first car was the only one that caught fire, Astorino said. "Everything is melted inside." There was not much damage from the second car back.
The train was full when the accident happened, Astorino said. "There were about 650 (people) total on the ride home."
The crash was the deadliest in Metro-North Railroad's history, said Marjorie Anders, a spokeswoman for the MTA. The previous deadliest crash happened in December 2013, when four passengers were killed and more than 70 were injured
in a derailment on the Hudson Line in the Bronx.
In October, the NTSB said an investigation of five Metro-North accidents
revealed "recurring safety issues, including inadequate and ineffective track inspection and maintenance, extensive deferred maintenance issues, inadequate safety oversight, and deficiencies in passenger car crashworthiness, roadway worker protection procedures and organizational safety culture."
Those accidents resulted in six fatalities and 126 injuries, according to the NTSB, which found "several safety management problems that were common to all of the accidents."
The day before the NTSB announced its findings, the MTA named David Mayer, a former NTSB managing director, as chief safety officer.
NTSB teams with expertise in several areas, including highway and rail traffic signals, crossing gates, fire propagation and recorders, will be at the scene for five to seven days, Sumwalt told reporters Wednesday morning in Washington as investigators prepared to travel to the site.
The investigation might take about 12 months, he said.